1. Field of the Invention
The invention pertains to a portable hypo/hyperthermia unit suitable for clinical medical use in cooling or heating selected portions of the body of a patient, to raise or lower the temperature thereof, particularly for cooling or heating at arterial sites.
2. Description of the Related Art
There are numerous circumstances in the medical field where raising or lowering the temperature of the body of a patient is warranted. As indicated in U.S. Pat. No. 7,637,931, for example, mild hypothermia (32-34° C., for instance) has proven to be successful in reducing neural damage from stroke, heart attack, head trauma, etc. Reduction of brain temperature by the use of helmets provided with means for circulating cool air or fluids have been disclosed, for example in U.S. Pat. No. 5,913,885 and PCT Published Application WO 98/56310. In U.S. Pat. No. 7,637,931, such devices, and also cooling pillows, have been described as unsatisfactory, particularly because of their bulk and specialized knowledge required for their use. U.S. Pat. No. 7,637,931 proposes to solve these problems by providing a shroud which, for example, encloses the head or even the entire body of the patient. Air is cooled or heated by Peltier effect devices and a series of valves which flow air over the cooling side of the Peltier device, over the heating side, or which bypasses the device altogether. The air is circulated by a blower through the shroud, where it cools or heats the body or respective body part. Such devices, however, are also bulky, and must rely on relatively large air passages to provide a volume of air necessary for the desired cooling effect. At times, it is considered medically advisable to raise body temperature, or to alternate heating and cooling.
Smith et al., in U.S. Pat. No. 7,022,093, discuss the disadvantages of using cooling devices such as gel packs, ice bags, etc., and proposes instead to use a brace or “wrap” which incorporates Peltier effect cooling devices which directly cool the body located within the brace. Disadvantages of such devices are that they are implemented for specific body parts, each requiring a different brace, and that the devices are relatively expensive. If the device is to be reused, it must be sterilized, or the Peltier elements and associated electronics must be removed and inserted into a new brace, which may also involve sterilization of the Peltier elements themselves.
Barrones et al. U.S. Published Application 2012/0179230 discloses a device for performing beauty treatments, physiotherapy, and hydrotherapy which employs Peltier devices for cooling of a fluid which is then circulated to a heat exchange device such as a face mask. When heating of the fluid is desired, or when the temperature of the cooled fluid is to be moderated, the fluid is passed through resistive heating units. The unit is complex, bulky, and due to the many internal parts, relatively expensive to manufacture. It is designed as a dedicated unit for stationary use, where it can be connected to a computer or LED screen for performance monitoring. The device cannot accompany a patient during transport, and is not designed for clinical use.
There has been a long felt need for a portable, self-contained device which is capable of performing both clinical hypothermia and hyperthermia, i.e. both cooling and heating of the body.